7 Easy Rosemary Growing Tricks for Beginners

No matter the season, you can find a dish that benefits from rosemary. Add it to marinades for summer-grilled meats, toss with roasted potatoes in the fall, and combine with flowers and herbs to create a fragrant potpourri.

If you’re a beginner interested in rosemary growing, you’re in luck. This herb is hardy in many locations and reappears year after year. However, knowing a few tricks can help you keep your rosemary plants healthy and enjoy a robust harvest.

I’ll cover a few beginner rosemary growing tips, including how to select the proper environment and plant, and how to provide the ideal care.

Know Rosemary’s Hardiness

Rosemary is a perennial herb that can come back year after year. However, it’s sensitive to cold and can die during the winter.

Most types of rosemary are winter-hardy in zones 7 and above. If you’re not sure which growing zone you’re in, you can easily find out here. If you live in growing zone 7 and above, you can expect your plants to successfully survive the winter outdoors and start regrowing the following spring.

If you live in zone 6, you can still grow certain varieties that can tolerate colder weather. ‘Arp’ is one of the best varieties if you’re concerned about low temperatures. Heavily mulching the base of the plant with straw or wood chips will help protect the roots and increase the chances of winter survival.

Winter temperatures in zones 5 and below get too cold for rosemary. You can still grow this herb in these areas, but you should expect to replant it each spring or bring it into a protected area, like a garage, during the winter.

Choose a Well-Draining Location

One of the key mistakes beginners make when growing rosemary is planting in the wrong location. Rosemary plants are native to the Mediterranean, where they thrive in the arid climate.

Plant rosemary in a dry and well-draining area. Avoid any spots with standing water or compacted soil, but don’t be afraid of sandy or slightly rocky areas.

If you’re growing rosemary in a container, choose one with drainage holes and use a soil mix with excellent drainage. A standard soilless potting mix works well, but you can also make your own mixture by combining equal parts peat moss or coco coir, perlite, and compost. 

Lots of Sun Is Key

Rosemary plants thrive in full sun and will struggle in shady areas. Choose a location that receives at least eight hours of daily sun. These plants can tolerate heat, so don’t be afraid of planting them in a spot that receives 12+ hours of sun in the summer.

If your plant appears stunted, discolored, or lacking fragrance, it may need more light. You can easily move potted plants to a brighter location or dig up and replant herbs growing in the ground.

Avoid Overwatering

Remember when I said rosemary likes well-drained soil? Well, that’s because it hates sitting in wet soil. Avoiding overwatering is another key to beginner rosemary growing.

Rather than watering on a schedule, check the soil moisture to determine if it’s time to grab the hose or watering can. Stick your finger into the top three inches of soil, and only water when it feels dry. Water slowly near the base of the plant until the soil is thoroughly moist. This type of deep watering encourages root growth and improves the plant’s overall health.

If you’re growing rosemary next to other herbs like parsley and cilantro, be aware that this woody perennial requires less water than the more tender greens. Rather than watering the whole area with sprinklers or a hose, apply water near the base of each plant so you can meet each herb’s moisture requirements.

Signs of overwatering can include yellow or brown leaves, wilting plants, or rotten roots. If you notice any of these, check the soil and cut back on watering if it’s already moist.

Give Plants Room to Breathe

Rosemary is susceptible to fungal diseases that can lead to discolored leaves and defoliation. Good air circulation helps prevent these pathogens from taking hold.

Proper plant spacing is one key part of allowing good air movement. Space rosemary plants two to three feet away from other plants. This may seem like excessive space if you’re starting with a small seedling, but your plant will quickly grow.

Since wet leaves are prone to fungal infections, avoiding overhead watering is another effective preventive measure. Applying water near the plant’s base is a better option.

Don’t Be Afraid to Prune

It’s easy to hesitate when your young rosemary plant finally puts on a few strong stems, but pruning actually helps it grow fuller and healthier. The best time to prune is the middle of spring and early summer, after the first flowers have faded.

You can start pruning once your rosemary is about eight inches tall. Find a shoot and use sharp and sanitized pruners to cut off the top three to six inches. Make sure you don’t remove more than one-third of the stem at once. This type of pruning will encourage bushier growth and prevent woody stems.

You can also prune rosemary to encourage good airflow and remove diseased stems. Trim off any discolored or rotten stems and discard them in your compost pile or an area far away from your remaining rosemary plants.

Avoid pruning in the fall, since this can encourage the plant to produce new growth that’s extra sensitive to cold. You can still remove diseased and damaged tissue in the fall.

Watch for Common Problems

Rosemary is generally easy to grow, but some problems do arise. Knowing the most common issues will help you address them as soon as they appear.

Root Rot

Root rot is the general term for a group of diseases that lead to rotten roots. As the disease progresses, the plants have difficulties taking up water and nutrients, leading to stunted and/or wilted plants. Planting in well-draining soil and avoiding overwatering can help prevent root rot.

If you suspect your plants have root rot, decrease the amount you water. Lightly infected plants will likely recover on their own in a few weeks to months.

Blight

Rosemary blight isn’t a specific disease but rather a term for diseases that cause brown leaves and stems. Botrytis and Rhizoctonia are two types of fungi that often cause these symptoms.

Avoiding overhead watering and providing excellent airflow are two ways to help prevent blight. If you suspect blight, you can prune off infected branches. Organic fungicides are rarely necessary, but they are a suitable last resort.

Sap-Sucking Pests

Small pests like aphids, spider mites, and mealybugs pierce rosemary leaves and drink their sap. A small number of these pests won’t harm the plant, but larger numbers can cause damage.

Encouraging beneficial predators can help keep these pest numbers low. You can also remove them by wiping them off with a soapy rag or spraying them with neem oil or insecticidal soap.